Pap Cheat Sheet

Getting your first "Pap smear" is a dubious rite of passage into American womanhood. Though we've all heard that we're supposed to get tested each year, we may not know lots of other important things about this infamous screening, like what it tests for, what the results mean and how often we really need one.

So, to clear up some of the misconceptions surrounding Pap tests (which is the correct terminology these days, since the "smear" technique is quickly being outmoded), here's a Pap cheat sheet:

What it is:The Pap test is named after the physician Georgios Papanikolaou, who pioneered the screening test. It involves taking samples of cells from the cervix (the bottom portion of the uterus). The cells are sent to a lab where they are microscopically examined to check for pre-cancerous changes.

What it isn't: Contrary to common belief, Pap tests do not check for vaginal or cervical infections. If you are concerned about infection, talk to your healthcare provider about other testing. Conversely, if you have been tested for infection, it doesn't mean that you've had your Pap.

What is a "thin Pap"? The thin-prep Pap test was approved by the FDA in 1996 and is now used in 90 percent of Pap tests done in the United States. Unlike the traditional Pap "smear," in which a sample of cells is smeared onto a slide, cells collected in the thin-prep Pap are tested in a liquid medium. The method of collecting cell samples is the same for both techniques, so the experience feels the same for the patient. Thin-prep Paps mean earlier detection of cervical cancer and longer intervals between Pap tests, provided your tests come back normal.

What do the results mean? A normal result means just that--the cells appear completely healthy. Abnormal results are classified according to how the cells look. Some changes are of "undetermined significance" and are usually managed by a more frequent screening schedule. Changes could be caused by recent sexual activity, or a yeast infection.

Other results that show varying levels of precancerous changes are usually investigated by colposcopy, an exam during which the cervix is examined with a magnifying lens and, sometimes, biopsies are taken. Depending on the results of the colposcopic biopsies, patients are treated in one of the following ways: more frequent Pap tests, cryotherapy (freezing abnormal-looking portions of the cervix with a special instrument) or LEEP (Loop Electrosurgical Excision Procedure, which involves removing abnormal tissue).

How often do you need one? According to the American Cancer Society, all women should have their first Pap test within three years of first having vaginal intercourse or when they turn 21 years old, whichever comes first. Screening should be done every year if the traditional test is used, or every two years using the newer liquid-based ("thin-prep") test. Ask your healthcare provider which test you will be given.

Most women can follow these guidelines for Pap test frequency from WomensHealth.gov:

• If you are younger than 30 years old, you should get a Pap test every year.
• If you are age 30 or older and have had three normal Pap tests for three years in a row, talk to your doctor about spacing out Pap tests to every two or three  years.
• If you are ages 65 to 70 and have had at least three  normal Pap tests and no abnormal Pap tests in the last 10 years, ask your doctor if you can stop having Pap tests.
• A woman who has had a total hysterectomy (removal of the cervix and the uterus) for reasons other than cancer or pre-cancer can stop having PAPs. If the cervix remains (partial hysterectomy), she should follow the above guidelines.

Women who have certain risk factors for cervical cancer, such as diethylstilbestrol (DES) exposure in utero, HIV infection or a weakened immune system due to organ transplant, chemotherapy or chronic steroid use should have lifelong annual Pap tests.

Hopefully this helps you understand what happens during a Pap test, and reminds you to call if you're due for your appointment!